In the aerospace industry, honeycomb products have been used as a core component for sandwich panels and boards that are resistant to buckling and bending. These honeycomb products each comprise a plurality of cells, which in cross-section have a generally hexagonal shape. Such products may be fabricated from aluminum, fiber paper or plastic, among other materials. A sandwich structure may be prepared having two cover layers or skins which are welded, adhesively bonded or otherwise secured to the honeycomb product to create a multilayered or multi-laminate material. Interest expressed in other industrial sectors concerning the use of lightweight sandwich structures is continually growing, due at least in part to the realization of its high strength properties while maintaining a relatively low structural weight per volume of product.
A multilayered or multi-laminate material having a honeycomb product as the core thereof may be used in the packaging industry. However, in automobile part packaging and comparable markets, such a product must compete with corrugated paperboard or corrugated plastic or like materials which may be produced quickly and relatively inexpensively.
U.S. Pat. No. 6,183,836 discloses a honeycomb core for use in a sandwich material in which the material of the honeycomb core is cut and then folded to create a plurality of hexagonal cells. Due to the process used to make the honeycomb product, including the complex folding of the cut sheet, the resultant structure may be expensive to manufacture.
A process for producing a folded honeycomb core for use in sandwich materials from a continuous uncut web is disclosed in U.S. Pat. No. 6,726,974. U.S. Pat. No. 6,800,351 discloses another process for producing a folded honeycomb core which includes scoring a corrugated material before rotating interconnected corrugated strips. The honeycomb core resulting from using either of these methods may have material which adds to the weight of the honeycomb core, but may not significantly improve the strength of the honeycomb core.
Regardless of which method is used to manufacture a honeycomb core, the resultant core may have a compressive strength in one direction which is higher than the compressive strength in another direction. Often the compressive strength in one direction is higher due to several layers of the material being overlapped; all the overlapped portions extending in the same direction. Accordingly, there is a need for a multilayered product which has an interior honeycomb layer having equal strengths in multiple directions.
There is further a need for a process for manufacturing a product, such as a honeycomb product, for use in a multilayered material which is less expensive and more efficient than heretofore known processes.